SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6baa79bd6523885988c62df97438d43af83327be1b2045fbf11be3024716d4f0' 
  AND token = 'awLP3Ol/OkZ/kZ+YJJQyRNX1rn1hhuWcLliftkvItN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}